This sample shows how you can bring up a dialog box, or any other type of window, while your application is running in DirectDraw's full-screen exclusive mode. Even devices that are non-GDI are detected and supported by creating a bitmap from their window contents and then blitting that to the device.
Source: (SDK root)\Samples\Multimedia\DDraw\Src\FSWindow
Executable: (SDK root)\Samples\Multimedia\DDraw\Bin
If you have more than one device, the sample starts by displaying a dialog box so that you can select which device to run the sample on. It then switches to full-screen exclusive mode and displays a dialog box and the mouse cursor.
Click on the Cancel or OK button to close the dialog and hide the mouse cursor. Press F1 to bring the dialog and cursor back. Press Esc to exit the program when the dialog is no longer displayed.
Most of the important code is in the Fswindow.cpp file.
The sample uses just the dynamic content mode, which constantly refreshes the dialog box to show which controls have focus, text in the edit field, and so on. The static content mode consumes less CPU time and would be good for pop-up windows that display help messages, for example.
It is important to understand that the content window can be any type of window. It could be an HTML Help window, or a window with a rich edit control to display formatted text. The window does not need to have a square clipping region; it could have a complex clipping region that fits the shape of the window you want to display.